The present invention relates to a power-saving infrared-detecting receiving system, and more particularly to a system controlled by a micro-controller and including an infrared module for detecting infrared signal and an ultra-low power-consuming and dependently powered predetector for detecting an infrared front guide signal. Whereby the receiving system is normally in a standby state with most system power being cut off and only a very low power being consumed by the predetector to detect an infrared front guide signal emitted by a remote controller. The power consumed by the receiving system can therefore be largely reduced.
Following the technological advancements, most domestic electric appliances for daily use, such as TV sets, sound systems, air conditioning systems, curtain systems, etc., are designed to be conveniently remotely controlled with infrared signals. A remote controller emits such infrared signals. An infrared-detecting receiving system is provided in the individual electric appliance to receive such infrared signals and a micro-controller in the receiving system is notified to drive the electric appliance.
In a conventional infrared-detecting receiving system, power is supplied from mains to each individual unit system contained in the receiving system. Such individual unit systems usually include a micro-controller and an infrared module. Wherein, the micro-controller is the main control unit of the receiving system. The infrared module receives a modulated infrared signal emitted by a remote controller. The modulated infrared signal is demodulated into an infrared signal having correct frequency and sent to the micro-controller at where the demodulated infrared signal is judged for correctness. When the signal is judged and determined to be a correct infrared signal, the receiving system enters into an operating state and a driving circuit therein is notified to start controlling movements.
The infrared module included in the above-described conventional infrared-detecting receiving system includes many very complicate circuits. FIG. 1 is a block diagram of an infrared module of this type. As shown, the infrared module mainly includes an infrared diode 11, a current-voltage converter 12, a low-pass filter 13, an amplifier 14, a bandpass filter 15, an automatic gain controller 16, and a waveform regulator 17. When a remote controller used together with the receiving system emits a commercial modulated infrared signal (38 kHz carrier modulation), the infrared diode 11 in the infrared module receives the modulated signal which is converted by the current-voltage converter 12 from current into voltage. The low-pass filter 13 removes high-frequency noises from the signal which is then amplified by the amplifier 14. The 38 kHz carrier modulation signal is then filtered by the bandpass filter 15 and is regulated in its magnitude by the automatic gain controller 16. Thereafter, the waveform regulator 17 modifies the waveform of the signal and the resultant signal is output to the micro-controller.
In the above-described conventional infrared-detecting receiving system, the infrared module must be constantly supplied with current to detect and receive a modulated infrared signal from the remote controller at any time. Since the aforesaid infrared module is composed of many complicate circuits, it consumes considerably high power (usually from about 1.5mA to about 3mA). When general dry batteries are used as the main power supply for the receiving system, as in the case of a curtain control system, a large amount of dry batteries is consumed and frequent replacement of new batteries is required. Such constant and high consumption of power is, of course, not economical.
It is therefore tried by the inventor to develop an infrared-detecting receiving system which eliminates the drawback of high power consumption existing in the conventional infrared-detecting receiving system.
A primary object of the present invention is to provide a power-saving infrared-detecting receiving system that includes an ultra-low power-consuming and independently powered predetector for detecting an infrared front guide signal, in addition to a micro-controller and an infrared module. This arrangement allows the receiving system to be normally in a standby state with most of its control units in a power-off state and only a very small current being consumed by the predetector for detecting an infrared front guide signal emitted by a remote controller at any time.
To achieve the above object, the present invention provides a receiving system which mainly includes a micro-controller serving as a main control unit in the receiving system. The micro-controller controls the supply of current to an infrared module for the same to receive a modulated infrared signal emitted by a remote controller used together with the receiving system. The received modulated infrared signal is demodulated into infrared signals of correct frequency and sent to the micro-controller at where the demodulated infrared signals are judged for their correctness. If the signals are determined to be correct, the receiving system enters into an operating state and a driving circuit thereof is notified to start controlling movements. The receiving system of the present invention also includes an ultra-low power-consuming and independently powered predetector which is capable of detecting a low-frequency infrared front guide signal emitted by the remote controller. When an infrared front guide signal is detected, a trigger signal is sent from the predetector to the micro-controller. At this point, the micro-controller enters into an operating mode and turns on system power to supply current to the infrared module for the latter to detect and receive a complete modulated infrared signal. That is, the receiving system can be normally in a standby state to turn off the system power with only a very low power supplied to the predetector to detect and receive an infrared front guide signal emitted by the remote controller. Whereby, an ultra-low power consumption is needed by the receiving system of the present invention.